首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   100764篇
  免费   8454篇
  国内免费   4360篇
电工技术   5806篇
技术理论   6篇
综合类   6354篇
化学工业   16766篇
金属工艺   6300篇
机械仪表   7097篇
建筑科学   8164篇
矿业工程   3450篇
能源动力   2956篇
轻工业   6375篇
水利工程   1678篇
石油天然气   7445篇
武器工业   815篇
无线电   10842篇
一般工业技术   11726篇
冶金工业   4963篇
原子能技术   1032篇
自动化技术   11803篇
  2024年   470篇
  2023年   1825篇
  2022年   3231篇
  2021年   4374篇
  2020年   3392篇
  2019年   2747篇
  2018年   2954篇
  2017年   3353篇
  2016年   3081篇
  2015年   4165篇
  2014年   4983篇
  2013年   5929篇
  2012年   6396篇
  2011年   6814篇
  2010年   5856篇
  2009年   5585篇
  2008年   5436篇
  2007年   5153篇
  2006年   5502篇
  2005年   4750篇
  2004年   3039篇
  2003年   2863篇
  2002年   2696篇
  2001年   2447篇
  2000年   2359篇
  1999年   2669篇
  1998年   2112篇
  1997年   1752篇
  1996年   1736篇
  1995年   1435篇
  1994年   1170篇
  1993年   751篇
  1992年   653篇
  1991年   447篇
  1990年   355篇
  1989年   304篇
  1988年   232篇
  1987年   151篇
  1986年   122篇
  1985年   73篇
  1984年   54篇
  1983年   44篇
  1982年   41篇
  1981年   29篇
  1980年   25篇
  1979年   18篇
  1978年   1篇
  1965年   1篇
  1959年   2篇
  1951年   1篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
11.
Zhang  Xi  Wang  Xianhai  Zhao  Hongke  Ordóñez de Pablos  Patricia  Sun  Yongqiang  Xiong  Hui 《Scientometrics》2019,119(3):1311-1344
Scientometrics - Altmetrics indices are increasingly applied to measure scholarly influence in recent years because they can reflect the influence of research outputs more timely comparing with...  相似文献   
12.
Chen  Xi  Zhao  Huan-jing  Zhao  Shu  Chen  Jie  Zhang  Yan-ping 《Scientometrics》2019,121(2):937-956
Scientometrics - Due to the development of academic, more and more attentions are paid to citation recommendation. To solve the citation recommendation problem, researchers begin to focus on the...  相似文献   
13.
Stream ciphers based on linear feedback shift register (LFSR) are suitable for constrained environments, such as satellite communications, radio frequency identification devices tag, sensor networks and Internet of Things, due to its simple hardware structures, high speed encryption and lower power consumption. LFSR, as a cryptographic primitive, has been used to generate a maximum period sequence. Because the switching of the status bits is regular, the power consumption of the LFSR is correlated in a linear way. As a result, the power consumption characteristics of stream cipher based on LFSR are vulnerable to leaking initialization vectors under the power attacks. In this paper, a new design of LFSR against power attacks is proposed. The power consumption characteristics of LFSR can be masked by using an additional LFSR and confused by adding a new filter Boolean function and a flip-flop. The design method has been implemented easily by circuits in this new design in comparison with the others.  相似文献   
14.
15.
16.
17.
Research funding has been seen as one of the most important resource in the reward system of science. And usage of publications denotes an interesting perspective of user behavior in scientific communication. This study aims to address the relationship between funding and Usage Count, which is a new metrics item established on the platform of Web of Science. Full records of 300,010 articles published in 2013 were downloaded in October 2015, and divided into six disciplines, including information science library science, education educational research, economics, computer science, materials science, and chemistry. Seven indicators were proposed to measure the impact, including Funding rate, Citation per paper, Usage rate, Usage per paper, Citation difference, Usage difference, and Conversion rate. It concluded funding has impact on usage and citation, and funded papers attract more usage, but varying in different disciplines. Usage Count can be used in the extension of citation metrics but with limits. This study originally engages with usage metrics and detected that there is positive correlation between usage and funding.  相似文献   
18.
Chen  Xin  Zhao  Bijun  Li  Shuti 《Semiconductors》2019,53(13):1792-1796
Semiconductors - The performance of InGaN/GaN multiple quantum well (MQW) solar cells with five different Si-doping concentrations, namely 0, 4 × 1017 cm–3, 1 × 1018 cm–3, 3...  相似文献   
19.
JOM - The Isa/Ausmelt smelting technology with a top submerged lance (TSL) has been extensively used in copper smelting processes. However, the TSL is extremely vulnerable to damage and failure...  相似文献   
20.
Three-dimensional (3D) YBO3:Tb3+ flower-like and dense flower-like hierarchitecture constituted of nanoflakes are solvothermally synthesized in the presence of polyborate precursors in the mixture of ethanol and water. The growth process of the YBO3:Tb3+ flowers and dense flowers was explored based on the time-dependent experiment and the results showed that the growth mechanism follows an in situ growth rather than self-assembly process as reported previously. YBO3:Tb3+ morphologies composed of nanoflakes are achieved by controlling the concentration of ethanol and dependence of photoluminescence on morphology was studied. Remarkable photoluminescence enhancement was observed for YBO3:Tb3+ with flower-like morphology demonstrating the potential of the microstructure in future applications as a green phosphor. Such a synthetic method and growth mechanism may be applied to fabricate complex 3D architectures of other materials.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号